technetium star

A star whose spectrum reveals the presence of the element technetium.
The first such stars were discovered in 1952 and provided the first direct
evidence for stellar nucleosynthesis
– the manufacture of heavier elements
from lighter ones in stellar interiors. Because the most stable isotopes
of technetium have half-lives of only a few million years, the only way
this element could be present inside stars is if it had made there in the
relatively recent past. Technetium is observed in some M
stars, MS stars, MC stars, S
stars, and C stars.